A new draft biological opinion issued by the National Marine Fisheries Service in Seattle, Wash., Wednesday morning has found that three commonly used herbicides are increasing the chance of extinction for threatened and endangered Pacific salmon and steelhead runs.

The report makes specific recommendations that, if implemented, could impact farming practices in the Central Valley, spawning grounds for some of the endangered fish.

The assessment by the federal fisheries service reverses earlier assurances from the U.S. Environmental Protection Agency that the three herbicides were “not likely to adversely affect” these dwindling salmon populations, say environmental groups.

The biological opinion prescribes measures to keep oryzalin, a preemergence herbicide used for control of annual grasses and broadleaf weeds in fruit trees, nut trees and vineyards; pendamethalin, used to control annual grasses and certain broadleaf weeds; and trifluralin, one of the most widely used herbicides in the United States, out of salmon waters in California, Washington, Oregon, and Idaho.

It is the fifth such plan issued under a court settlement with fishermen and conservationists.

The new protections, which must be implemented within one year of a final Biological Opinion, include:

• Prohibiting aerial applications of the pesticides within 300 feet of salmon waters.

• Mandating a 10-foot vegetated strip or a 20-foot no spray zone between salmon waters and places where these herbicides are applied.

• Mandatory reporting of fish kills near where these chemicals were applied.

“This is a huge step forward for the health of our rivers,” says Aimee Code, an environmental health associate at the Northwest Center for Alternatives to Pesticides. “The true solution is to expand the use of non-chemical solutions.”

The 780 page assessment says that if these pesticides are used as currently authorized, they are “likely to jeopardize the continued existence” of threatened and endangered salmon and steelhead populations.

“The federal government has just acknowledged that these three chemicals are washing off into our rivers and streams and harming west coast salmon runs and who knows what else,” says Steve Mashuda of Earthjustice. “It is time for the government to stand up to pesticide industry and impose these much needed restrictions,” he concluded.

It’s not just farmers who would be impacted. All three herbicides can be used in lawns and landscaping and are also registered for use along highway rights-of-way.